Service Guide

TroubleshootingGuide
31|Page
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REPLACINGTHEHEATEXCHANGER
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Therearemanypossiblecausesofaheatexchangerfailure:
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• Contaminated air with  a high level of dust, lint, sand, grease, aerosols or other contaminants,
can become airborne and enter the air intake.The contaminants build up within the fan and
burner assembly causing abnormal flame conditions due to
 lack of combustion air, damaging
manycomponentsoftheunit.
• Scalecanbuildupfromveryhardwater.Limescalewillformontheinsideoftheheat
exchangertubesreadilyathightemperatures.Thisscaleprohibitsheatfromreachingthewater
whichcausesexcessiveheatwithintheheat
exchangercopper,anditwilleventuallyburnand
leak.
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Alongwithchangingtheheatexchanger,itisimportanttoidentifytheCAUSEoftheneedfor
replacement,andfixtheproblemsoitdoesnotoccuragain.
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1) TOOLS
‐Gatherthefollowingmaterialstogether:
a. Degreaserinapumpactionbottle
b. Sheetof100GritSandpaper
c. #2PhilipsScrewDriver
d. Needle‐NosedPliers
e. AirCompressor
f. Towels
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2) PREPARETHEUNIT
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a. POWER
‐Disconnectpowertoyourunit.
b. GAS
‐Shutoffthegassupplytotheunit.
c. WATER
–Draintheunit.Refertop.21forinstructions.
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3) REMOVEMANIFOLD/GASASSEMBLY,BURNER
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a. Followstepsoftheprevioussection,“CleaningtheCombustionComponents”.Thiswilltellyou
howtoremovethePCB,manifold/gasassembly,andburner
4) VENTINGMANIFOLD
–Exhaustfrombothheatexchangerscombinetoexitoutofasingleflue
a. Removeall14exteriorscrews
b. Removeall14interiorscrews
c. Theventmanifoldmaynowberemoved
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Figure34 Figure35
14screws14screws